Clean energy advocates will soon be able to add a new source of energy to their roster - osmosis. Or, in other words, energy based on a natural phenomenon arising from the contact of fresh and salt water through the membrane.
Researchers at the Laboratory of Nanoscale Biology have succeeded in creating an osmotic energy system that has shown unprecedented efficiency. The innovation lies in the liquid-separating membrane, just three atoms thick.
The concept of the system is quite simple. The membrane separates 2 liquids with different salt concentration from each other. The salt ions of the solution with a higher concentration will penetrate into the adjacent container until "equilibrium" occurs between them. This is the essence of osmosis.
Since an ion is an electrically charged particle, the movement of salt ions can be used to generate an electric current. Due to its properties, the membrane allows positively charged ions to pass through and repels most negatively charged particles. As a result, tension is created between the two fluids.
According to the head of the Laboratory of Nanoscale Biology, Alexander Radenovich, the potential of the system is enormous. Scientists estimate that a 1 square meter surface covered with nanomembranes can generate up to 1 MW of electricity, which is enough to power 50, 000 energy-saving light bulbs.
A big advantage is the fact that the molybdenum disulfide from which the membrane is made is quite common in nature or can be grown by chemical vapor deposition. This creates the preconditions for the industrial production of electricity.
Norway, the Netherlands, Japan, and the United States are showing interest in osmotic energy, where pilot projects are already underway to install electric generating membrane systems in estuaries of rivers flowing into the sea.